Video transferring system, video transmission apparatus, video reception apparatus and video transferring method

ABSTRACT

In a transmission side, a layer adjusting unit performs an adjustment to store a scalable encoded video data in a memory, select and output a scalable data of a base quality as a real-time video, read from a memory a scalable data of an enhancement quality based on the designation of a enhancement quality and a transmission period of time, and output the scalable data of an enhancement quality together with a real-time scalable data. In the receiving side, a layer synthesizing unit synthesizes and outputs a real-time video at normal times, and lowers the real-time video to a quality of the base layer if there is an enhancement quality video of a designated period of time, thereby reading the base quality layer data corresponding to the designated video from the memory ( 153 ) and synthesizing the data with the enhancement quality video to output the resulting data.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromJapanese Patent Applications No. 2010-240010, filed on Oct. 26, 2010,the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a video transferring system, a videotransmission processing apparatus and reception processing apparatusthereof, and an video transferring method for transferring an videostream of, for example, a surveillance camera.

BACKGROUND

A conventional video transmission system transfers an video stream takenby a surveillance camera to a reception apparatus through a networkwhile recording the video stream in a transmission apparatus during apredetermined period of time, and displays the video stream on a monitorof the reception apparatus in real time. When there is something tofocus on in the video stream displayed on the monitor in real time, auser may perform rewind and playback operations.

Recently, the performance of a surveillance camera has continuously beenenhanced and accordingly it has become possible to have high qualityvideos (particularly, resolution). Since such high quality videos have agreat amount of data, it has been suggested that a lower quality videodata be transferred at normal times and a high quality video data beprovided only when a user requests playback.

However, since a bandwidth is highly occupied while a high quality videois supplied, it is very difficult to transfer a low quality video to bedisplayed in real time with the high quality video.

Additionally, it has been known that a video stream is transmitted as ascalable encoded data.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a configuration of a videotransferring system according to an embodiment of the presentdisclosure.

FIG. 2 is a conceptual view showing a layer configuration of transferredvideo data according to the embodiment.

FIG. 3A is a conceptual view showing a band distribution of the scalabletransmission according to the embodiment.

FIG. 3B is a conceptual view showing a band distribution of playbackaccording to the embodiment.

FIG. 4A is a conceptual view showing a layer configuration in the casewhere a plurality of video streams are transferred according to theembodiment.

FIG. 4B is a conceptual view showing a bandwidth distribution in thecase where the plurality of video streams are transferred according tothe embodiment.

DETAILED DESCRIPTION

Hereinafter, embodiments of the present disclosure will now be describedin detail with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of a videotransferring system according to an embodiment. It is assumed hereinthat the system is a surveillance system that requires a real-timedisplay.

In FIG. 1, a video capturing apparatus 11 denotes capturing apparatussuch as a surveillance camera. The video stream taken by the videocapturing apparatus 11 is scalable-encoded by an encoder 12 to therebybe sent to a transmission apparatus 13.

The scalable encoding process of the encoder 12 encodes video dataaccording to, for example, an H.264/SVC format. In the scalable encodingprocess, as shown in FIG. 2, the transmission videos are divided intothree layers of a lowest quality, a base quality and an enhancementquality. The encoded data of a lowest quality video is provided in abase layer A, the encoded data of a differential video of a lowestquality video and a base quality video are provided in an extensionlayer (α) B, and encoded data of a differential video of an enhancementquality video and a base quality video are provided in an extensionlayer (β) C.

In the transmission apparatus 13, video data which has beenlayer-encoded in the encoder 12 is input to a layer adjusting unit 131.The layer adjusting unit 131 stores the input video data in a memory132, and, at the same time, selects and outputs encoded data of the basequality video, that is, encoded data of the base layer A and theextension layer (α) B. In addition, based on a designated period of timeand enhancement quality by a period and quality controlling unit 133,the layer adjusting unit 131 reads from the memory 132 the encoded dataof the extension layer (β) C corresponding to the designated period oftime, and outputs the data together with a real-time video encoded data.At this time, the real-time video encoded data for transmission islimited to only the base layer A, so that the entire bandwidth may be inits allowable range.

The video encoded data output from the layer adjusting unit 131 is sentto a transmission processing unit 134, layer-multiplexed in apredetermined datastream format to be transmitted from the transmissionapparatus 13, and sent to a reception apparatus 15 through a network 14.

In the reception apparatus 15, the video encoded data transmitted fromthe network 14 is received by a reception processing unit 151 and isdivided into each layer thereby being sent to a layer synthesizing unit152. The layer synthesizing unit 152 distinguishes the transmitted datafor each layer and stores the data in a memory 153 and, at the sametime, layer-synthesizes a layer for each video and sends thelayer-synthesized video to a display unit 16. The display unit 16decodes the video encoded data and outputs the decoded data. If thedisplay unit 16 received the encoded video data of the designated periodof time, the display unit 16 decodes the video encoded data of thedesignated period and displays the decoded video together with thereal-time video data (the video may be displayed in each of separatescreens).

The reception apparatus 15 includes a period and quality selecting unit154. in the case where a user requests a rewind replay with theenhancement quality video when monitoring a displayed video, the requestis transmitted to the period and quality controlling unit 133 in thetransmission apparatus 13 through the network 14 from the period andquality selecting unit 154.

In the above, the embodiment where a user inputs a request for a rewindreplay with an enhancement quality video has been described. However, inthe case where something abnormal condition is detected by motiondetection, sound detection, face recognition and so on, it may triggeran automatic request for the enhancement quality video corresponding tothe detected abnormal condition.

FIG. 3A is a conceptual view showing an aspect of transmitting a rewindreplay video together with a real-time video in the transmissionapparatus 13, and FIG. 3B is a conceptual view showing an aspect of theplayback display in the reception apparatus 15 according to theembodiment. First, as shown in FIG. 3A, at normal times, thetransmission apparatus 13 transmits real-time video encoded data of abase quality through the base layer A and the extension layer (α) B(video encoded data of the base layer A and differential video encodeddata of the extension layer (α) B) #1, #2, . . . in a bandwidth. Thisdata is stored in the memory 153 for a predetermined period of time.

It is assumed herein that the rewind replay for the video encoded data#2 of the enhancement quality has been requested at the time of t. Thetransmission apparatus 13 reads the differential video encoded data #2of the enhancement quality from the memory 132 when receiving a requestfor a rewind replay of the video encoded data #2 from the receptionapparatus 15. At this time, the layer adjusting unit 131 stopstransmitting the extension layer (α) B of the video encoded data #5 inreal time, and transmits the differential video encoding data #2 of theenhancement quality having been read from the memory 132 in thecorresponding bandwidth together with the video encoded data #5 of thelowest quality (i.e., base layer A of the video encoded data #5).

The layer synthesizing unit 152 in the reception apparatus 15 outputsthe real-time transmitted video data #5 of the lowest quality to thedisplay unit 16 and synthesizes the differential video encoded data ofthe extension layer (β) C transmitted during the period of time with thepast video encoded data (the video encoded data of the base layer A andthe differential video encoded data of the extension layer (α) B) whichis read from the memory 153 to generate the video encoded data #2 of theenhancement quality and output it to the display unit 16. Accordingly,the real-time transmitted video is continuously displayed in the lowestquality without stopping, while a video of rewind replay is displayed inan enhancement quality.

The embodiment has been described for the video transferring systemwhich transmits the encoded video stream of one channel. A videotransferring system of the present disclosure may have a plurality ofsurveillance cameras and transmit encoded video streams of multiplechannels.

FIG. 4A and FIG. 4B are conceptual views showing the case where aplurality of video streams are transmitted within the limited bandwidth(corresponding to four layers).

FIG. 4A shows the scalable encoding structures of the first video streama and second video stream b, each of which has three layers of the baselayer A, extension layer (α) B and extension layer (β) C, like the layerstructure shown in FIG. 2.

FIG. 4B is a conceptual view showing an aspect of the scalabletransmission of the first video stream a and second video stream b whichare scalable-encoded. At normal times, both the video streams a and bare transmitted in the base quality, i.e., the base layer A and theextension layer (α)B, and at least the base layer data a1, a2, a3, . . ., b1, b2, b3, . . . are transmitted in real time.

At time t1, when a transmission of the enhancement quality for thesecond stream b1 is requested, the first video stream a2 is limited tothe base layer A (the lowest quality), and the second video steam b1 istransmitted in the extension layer (β) C. Accordingly, although thefirst video stream a2 becomes a lowest quality video, the second videostream b1 may be displayed in an enhancement quality.

At time t2, when the transmission of the second video stream b1 of theenhancement quality is ended, the base layer A and extension layer (α) Bof the first video stream a3 are transmitted, and the second videostream b3 is limited to the base layer A (the lowest quality), and theextension layer (α) B of the first video stream a2 is transmitted.Accordingly, although the second video stream b3 becomes a lowestquality video, the extension layer (α) B of the first video stream a2having been limited at the time of t1 may be interpolated, and at leastthe reception apparatus may perform a rewind replay of the first videostream a2 of the base quality.

Also, although not shown in the drawings in detail, when the first videostream a and second video stream b are transmitted in real time, one ofthe video streams may be limited to a lowest quality video and the othervideo stream may be enhanced to an enhancement quality video.

As described above, in the case where a plurality of video streams issimultaneously transmitted, each of the videos is scalable-encoded andone of the video streams decreases in its quality according to a requestfor the enhancement quality with respect to another video stream,thereby enabling transmission of the enhancement quality data of theother video stream during a designated period of time. In other words,for example, when there is something to focus on when monitoring aplurality of videos, a user may rewind the corresponding video andconfirm the video in high quality. At this time, the video not beingrewound also needs to be monitored on a real-time screen. The videostream corresponding to the video not being rewound is set to the lowestquality and thus it is possible to confirm the video stream beingrewound in a high quality while maintaining the video stream not beingrewound to be displayed in a real-time.

Also, in the embodiment described above, a differential video isprovided in such a manner that one video reduces its quality therebyenhancing the quality of the other video, and thus a base quality videocannot be obtained during the period of time in which the video isdecreased in quality. Therefore, in the case where there is a margin inthe bandwidth, the differential video encoded data of the enhancementquality (α) B is transmitted by expending time, and stored in thereceiving side memory 153. Accordingly, the reception apparatus 15 maydisplay at least the base quality video.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the disclosures. Indeed, the novel methods and apparatusesdescribed herein may be embodied in a variety of other forms;furthermore, various omissions, substitutions and changes in the form ofthe embodiments described herein may be made without departing from thespirit of the disclosures. The accompanying claims and their equivalentsare intended to cover such forms or modifications as would fall withinthe scope and spirit of the disclosures.

What is claimed is:
 1. A video transferring system comprising: atransmission apparatus that transmits a video stream as a scalableencoded data including a base layer and a first base quality extensionlayer in real-time; and a reception apparatus that receives the videostream via a network, wherein the transmission apparatus comprises: atransmitter that transmits, in response to receiving a rewind signal, asecond base quality extension layer instead of the first base qualityextension layer with the base layer within a limited bandwidth, whereinthe reception apparatus comprises: a receiver that receives the videostream and divides the scalable encoded data into each layer; a memorythat stores the real-time transmitted base layer and the first basequality extension layer; a layer synthesizer that synthesizes thereal-time transmitted base layer and first base quality extension layerto create a base quality video signal at normal times, and synthesizesthe pre-stored base layer and first base quality extension layer, andthe real-time transmitted second base quality extension layer to createa high quality rewind video signal in response to the rewind signal; anda display that displays the created high quality rewind video signal atthe same time as displaying the base layer.
 2. The system of claim 1further comprising: a surveillance camera that records a real-time videosignal; and an encoder that encodes the real-time video signal into thebase layer, the first base quality extension layer, and the second basequality extension layer.
 3. The system of claim 1 wherein the videostream is encoded in H.264/SVC format.
 4. The system of claim 1 whereinthe base layer comprises the lowest quality video signal, the first basequality extension layer comprises an intermediate quality video signal,and the second base quality extension layer comprises a high qualityvideo signal.
 5. The system of claim 1 wherein the display displays thebase layer as a real-time video signal.
 6. A video reception apparatusthat receives a video stream transmitted in real-time as a scalableencoded data including a base layer and a first base quality extensionlayer via a network, comprising: a receiver that receives the videostream and divides the scalable encoded data into each layer; a memorythat stores the real-time transmitted base layer and the first basequality extension layer; a layer synthesizer that synthesizes thereal-time transmitted base layer and first base quality extension layerto create a base quality video signal at normal times, and synthesizesthe pre-stored base layer and first base quality extension layer, and areal-time transmitted second base quality extension layer instead of thefirst base quality extension layer with the base layer within a limitedbandwidth to create a high quality rewind video signal in response tothe rewind signal; and a display that displays the created high qualityrewind video signal at the same time as displaying the base layer. 7.The apparatus of claim 6 wherein the video stream is encoded inH.264/SVC format.
 8. The apparatus of claim 6 wherein the base layercomprises the lowest quality video signal, the first base qualityextension layer comprises an intermediate quality video signal, and thesecond base quality extension layer comprises a high quality videosignal.
 9. The apparatus of claim 6 wherein the display displays thebase layer as a real-time video signal.
 10. A video transferring methodcomprising: first transmitting a video stream as a scalable encoded dataincluding a base layer and a first base quality extension layer; secondtransmitting, in response to receiving a rewind signal, a second basequality extension layer instead of the first base quality extensionlayer with the base layer within a limited bandwidth; receiving thevideo stream via a network; dividing the scalable encoded data of thereceived video stream into each layer; storing the real-time transmittedbase layer and the first base quality extension layer in a memory;synthesizing the real-time transmitted base layer and first base qualityextension layer to create a base quality video signal at normal times,and synthesizes the pre-stored base layer and first base qualityextension layer, and the real-time transmitted second base qualityextension layer to create a high quality rewind video signal in responseto the rewind signal; and displaying the created high quality rewindsignal at the same time as displaying the base layer.
 11. The method ofclaim 10 wherein the video stream is encoded in H.264/SVC format. 12.The method of claim 10 wherein the base layer comprises the lowestquality video signal, the first base quality extension layer comprisesan intermediate quality video signal, and the second base qualityextension layer comprises a high quality video signal.
 13. The method ofclaim 10 wherein the displaying displays the base layer as a real-timevideo signal.